Location permission handling in Marshmallow and above. (Permissions at runtime)

MainActivity.java

 void enableGPS() {
       
            //   locMan = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
            if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                    ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1);

                }
                else
                    checkIfGPSIsOn(locMan, this);
            }
            else
                locMan.requestLocationUpdates(LocationManager.GPS_PROVIDER, 30000, 100, this);


    }
    
    
    //----------------------------------------------------------------------------------------------------------------------
    
    
    @SuppressWarnings({"MissingPermission"}) @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case 1: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    // permission was granted




                    locMan.requestLocationUpdates(LocationManager.GPS_PROVIDER, 30000, 100, this);


                } else {

                    // permission denied
                    Toast.makeText(this, "GPS Disabled, enable GPS and allow app to use the service. Or app will not work properly", Toast.LENGTH_LONG).show();
                }
                return;
            }

            // other 'case' lines to check for other
            // permissions this app might request
        }
    }
    
    //----------------------------------------------------------------------------------------------------------------------
      
      
    protected void checkIfGPSIsOn(LocationManager manager, Context context) {
        if (!manager.getAllProviders().contains(LocationManager.GPS_PROVIDER)) {
            AlertDialog.Builder builder = new AlertDialog.Builder(context);
            builder.setTitle("Location Manager");
            builder.setMessage("Masjid Locator requires a device with GPS to work");
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    finish();
                }
            });
            builder.create().show();
        } else {

            if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
                //Ask the user to enable GPS
                AlertDialog.Builder builder = new AlertDialog.Builder(context);
                builder.setTitle("Location Manager");
                builder.setMessage("Masjid Locator would like to enable your device's GPS?");
                builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //Launch settings, allowing user to make a change
                        Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                        startActivity(i);
                    }
                });
                builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //No location service, no Activity
                        finish();
                    }
                });
                builder.create().show();
            }
        }
    }